A number of experiments will explore the effects of several types of influences on the development of prosocial behavior, behavior that benefits others (helping, sharing, etc.). It is hoped that the findings will contribute both to a theory of prosocial development and to our practical knowledge of how to enhance prosocial behavior of children. Of primary interest is the effect of three types of influences: "responsible action," that is, participation in prosocial behavior; verbal information, such as induction, pointing out the beneficial consequences for others of prosocial behavior, and self reinforcement, viewed as feedback to the self about the value of prosocial behavior; and indirect in contrast to direct instruction, when children learn to behave prosocially by acting as collaborators of an adult in teaching others to be helpful. Individual differences among children in relevant characteristics will also be studied, as they may modify the influence treatments, may show whether children with different characteristics learn best from different types of training, and may provide information about the relationship between personality characteristics and prosocial behavior. Both the specific and generalized effects of treatments, both immediate and delayed effects will be evaluated. Extensive and repeated experimental treatments will be employed so that they can be reasonably expected to bring about such increases in prosocial behavior. A variety of tests of prosocial behavior will be used, providing opportunity to also evaluate consistency in prosocial behavior across different situations and different types of benefits produced.